Novel Ceramic-Grafted Separator with Highly Thermal Stability for Safe Lithium-Ion Batteries

Abstract

The separator is a critical component of lithium-ion batteries (LIBs), which not only allows ionic transport while it prevents electrical contact between electrodes but also plays a key role for thermal safety performance of LIBs. However, commercial separators for LIBs are typically microporous polyolefin membranes that pose challenges for battery safety, due to shrinking and melting at elevated temperature. Here, we demonstrate a strategy to improve the thermal stability and electrolyte affinity of polyethylene (PE) separators. By simply grafting the vinylsilane coupling reagent on the surface of the PE separator by electron beam irradiation method and subsequent hydrolysis reaction into the Al solution, an ultrathin AlO layer is grafted on the surface of the porous polymer microframework without sacrificing the porous structure and increasing the thickness. The as-synthesized AlO ceramic-grafted separator (AlO-CGS) shows almost no shrinkage at 150 °C and decreases the contact angle of the conventional electrolyte compared with the bare PE separator. Notably, the full cells with the AlO-CGSs exhibit better cycling performance and rate capability and also provide stable open circuit voltage even at 170 °C, indicating its promising application in LIBs with high safety and energy density.

Separator Membranes for High Energy‐Density Batteries

“…Electron beam irradiation is an alternative method to change the surface modification of separators. For instance, in 2016 and 2017 the group of Cao presented a novel simple approach to prepare an inorganic ceramic‐grafted PE separator (CGS) by ionization‐radiation grafted and hydrolyzed process , . Methyl methacrylate (MMA) and glycidyl methacrylate (GMA) were grafted onto the surface of PE membranes by electron beam irradiation.…”

A highly efficient surface modified separator fabricated with atmospheric atomic layer deposition for high temperature lithium ion batteries

“…LIBs have been developed with good pace, both in research and commercialization from the last three decades. There is huge increase in its energy density of more than two‐fold magnitude, if compared with the very first introduced LIBs manufactured by Sony back in 1991 11 . However, having this continuous rapid growth, various problems linked to this technology are to be resolved; for attaining high power density, battery safety, better performance at high and low temperatures, reducing cost, and enhancement of energy density.…”

“…Atomic layer deposition (ALD) is a versatile technology which enables a ultra‐thin and conformal layer with accurate and controlled thickness without any compromise on its uniformity 23 . Since its inception, the applications of ALD have greatly expanded, especially in electronic devices like organic light emitting diode, 24 organic light emitting transistor, 25 organic thin film transistor, memristor, 26 and solar cells on flexible substrates 11 . Moreover, majority of such substrates possess high sensitivity for elevated temperatures.…”

Electrolytes for Dual‐Carbon Batteries

“…Developing alternative energy sources such as wind, solar, waves, and tidal energy, has minimized fossil fuel consumption and reduced greenhouse gas emissions. To efficiently utilize these intermittent renewable resources, researchers have developed new energy storage technologies, among which the lithium‐ion battery (LIB) is the dominant type used in modern consumer electronics and electric vehicles (EVs) . Currently available LIBs have high energy densities and excellent longevity.…”

“…To efficiently utilize these intermittent renewable resources, researchers have developed new energy storage technologies, among which the lithium-ion battery (LIB) is the dominant type used in modern consumer electronics and electric vehicles (EVs). [3][4][5][6] Currently available LIBs have high energy densities and excellent longevity. Their relative low charge/discharge rate and power density, however, are limitations that severely hinder their application in future EVs.…”